Network slice selection in wireless telecommunication networks

ABSTRACT

A wireless telecommunication system may utilize multiple network slices, each of which may implement a different core network. In order to route initial attach requests to appropriate network slices and corresponding core networks, a mobility management component sends a received initial attach request to a network slice selector. The network slice selector queries a selection policy function to obtain a designation of a particular network slice to which the attach request should be directed. The network slice selector then sends a redirect request to the mobility management component, instructing the mobility management component to resend the attach request to the designated network slice.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of and claims priority to U.S. patentapplication Ser. No. 15/451,493, filed Mar. 7, 2017, which claimspriority to U.S. Provisional Patent Application No. 62/456,943 filedFeb. 9, 2017, of the same title, which are incorporated herein byreference in their entirety.

BACKGROUND

Wireless communication networks face many challenges due to rapidincreases in the numbers of network users and the wide-spread use ofmobile and other wireless applications.

Network slicing is a technology that has been proposed to enhanceflexibility in wireless communication networks. Network slicing allowsmultiple logical networks to operate using a common underlyinginfrastructure. Network slicing can reduce costs of deployments,increase the efficiencies of physical infrastructures, and provideflexibility in the types of services that may be offered to differentusers.

A slice-based communications network can have multiple software-definedcore networks, referred to as slices, each of which may be optimized fora different type of service. For example, an LTE (Long-Term Evolution)core network can be provided for 4G (4^(rd)-Generation) LTE services andan IMS (IP Multimedia Subsystem) core network can be provided formultimedia messaging. Generally, network slices can be provided for manydifferent purposes, such as Internet browsing, voice communications,industrial control, home automation, IoT (Internet of Things), etc.Furthermore, different slices may be configured to provide differentQualities of Service (QoS). For example, one core network may bedesigned for low latency while another core network might be designed toprovide fast streaming.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description is described with reference to the accompanyingfigures. In the figures, the left-most digit(s) of a reference numberidentifies the figure in which the reference number first appears. Theuse of the same reference numbers in different figures indicates similaror identical components or features.

FIG. 1 is a block diagram of a wireless telecommunication system thatimplements techniques for selecting from multiple available networkslices.

FIGS. 2 is a flow diagram illustrating an example method of directingnetwork attach requests to individual network slices.

FIG. 3 is a flow diagram illustrating an example method of selecting oneof multiple individual network slices.

FIG. 4 is a communication sequence diagram illustrating an examplecommunication sequence for routing initial attach requests to selectednetwork slices.

FIG. 5 is a block diagram of an example computing device that may beconfigured to implement various functionality of a wirelesstelecommunications system.

DETAILED DESCRIPTION

Described herein are systems, configurations, interfaces, and techniquesthat may be used within wireless telecommunication networks to enableand enhance the use of virtual network slices.

A wireless communication device, referred to as a UE (user equipment),communicates through a RAN (radio access network) with a mobilitymanagement component when connecting to a wireless communicationnetwork. In non-sliced networks, upon receiving an initial attachrequest from the UE the mobility management component selects anappropriate mobility controller of the network, such as an SGW (ServingGateway) of an LTE (Long-Term Evolution) network. In traditional 4Gsystems, the mobility controller is selected primarily based ongeographical considerations, so that a nearby mobility controller isselected to provide services for a particular UE. In slice-basedsystems, however, the attach request needs to be sent to and processedby an appropriate one of multiple available networks slices, each ofwhich might implement a core network for a different type of service.

In certain embodiments described below, attach requests are sent fromthe mobility management component to a network slice selector. Thenetwork slice selector in turn queries a slicing selection policyfunction, which provides information to the network slice selectorregarding which of multiple available network slices should be selectedto handle a particular initial attach request. The network sliceselector then redirects the initial attach request to the selectednetwork slice.

FIG. 1 shows an example wireless telecommunication network or system 100that implements network slicing. Note that FIG. 1 shows only thosecomponents of the system 100 that are most relevant to the currentdiscussion. In particular, FIG. 1 shows top-level components involved inhandling an initial attach request from a wireless communication device102, which is also referred to herein as a UE (User Equipment) 102. Inpractice, the system 100 may have many other components and functionalelements, in addition to those shown.

The system 100 has multiple network slices 104, three of which are shownin FIG. 1 for purposes of illustration, although the system 100 may haveany number of network slices 104. In certain embodiments, each networkslice 104 may correspond to or comprise a dedicated core network.Different core networks may be provided for different types of services,for different types of customers, for different types of traffic, toprovide different levels of QoS (Quality of Service), etc.

In certain embodiments, the network slices 104 may comprisesoftware-defined networks, and may at times be referred to as “virtual”network slices. In certain situations, network slices may be dynamicallycreated and destroyed in response to increasing and decreasing demandsfor services. Dedicated network slices may also be dynamically createdfor certain customers and certain types of customers.

The UE 102 may comprise a wireless communication device such as asmartphone, or may comprise any other device having cellular or otherwireless communication capabilities, such as tablet computers, wearabledevices, controllers, entertainment devices, electronic book readers,automation equipment, automotive equipment, monitoring equipment,security equipment, media devices, etc.

An initial attach request is sent by the UE 102 through a RAN (RadioAccess Network) 106 to a mobility management component 108. In 4G(4^(th) Generation) LTE (Long-Term Evolution) networks, the mobilitymanagement component 108 comprises what is known as an MME (MobilityManagement Entity). In next-generation 5G (5^(th) Generation) systems,the mobility management component 108 may be referred to more generallyas a control plane function.

The mobility management component 108 is configured to respond to aninitial attach request by sending a create session request to a networkslice selector 110, also referred to herein as a slice selector and/or anetwork selector. In LTE networks, the create session request is sentover a logical communication interface that is referred to as an S11interface. The S11 interface is typically used for messaging between theMME and SGW (Serving Gateway) of an LTE network. In 5G networks, thecreate session request may be sent over a logical communicationinterface that is referred to as an NG4 interface. The NG4 interface istypically used for messaging between the control plane function and theuser plane forwarding function of a 5G network.

In response to receiving a create session request, the network sliceselector 110 determines which of the available network slices 104 shouldbe used to provide services for the requesting UE 102, and redirects thecreate session request to the selected network slice 104. For example,the create session request may be directed to a gateway component 112 ofthe selected network slice. In an LTE network, the gateway component 112may comprise an SGW. In a 5G network, the gateway component may comprisea user plane forwarding function.

In order to select one of the network slices 104, the network sliceselector 110 queries a slice selection policy function 114. The sliceselection policy function 114 may comprise a physical or logicalcomponent. In some cases, the slice selection policy function 114 may beimplemented by the network slice selector 110.

The slice selection policy function 114 selects one of the networkslices 104 based on policies 116, which may be provided or defined bythe provider of the system 100, such as a telecommunications provider.The selection of a network slice 104 may also be based on other inputs,obtained from other system components. As an example, the sliceselection policy function 114 may receive information from a networkslice orchestrator 118 regarding currently instantiated and availablenetwork slices. In particular, the orchestrator may provide informationregarding the IDs and network addresses of available network slices andthe services to which the network slices correspond. The orchestrator118 may also provide information regarding the characteristics ofprovided services, such as QoS information regarding the servicesprovided by individual network slices. In some systems, the networkslice orchestrator 118 may be accessible using REST (RepresentationalState Transfer) network communication interfaces.

Aa another example, the slice selection policy function 114 may receiveinformation from subscriber information databases 120, such as an SPR(Subscriber Profile Repository) or NDS (name domain system) in LTEsystems, or a UDM (User Data Management) function in 5G systems. Thesubscriber information databases 120 may provide a user profileindicating information regarding the device from which the attachrequest has been received, such as subscribed services, contracted QoS(Quality of Service) parameters, subscriber category, and chargingrelated data.

As yet another example, the slice selection policy function 114 mayreceive information from analytics components 122 of the system 100. Theanalytics components 122 may indicate information such as relativecongestion of the different network slices 104. Selection of aparticular network slice may at times be performed in order to balanceloads or congestion of available network slices. As with theorchestrator 118, the analytic components 122 may be accessed using RESTnetwork communication interfaces.

The information obtained from the orchestrator 118, the subscriberinformation databases 120, the analytic components 122, and possiblyother sources is evaluated against the policies 116 by the sliceselection policy function 114 to select one of the network slices 104and to return an identification of the selected network slice 104 to theslice selector 110. In some embodiments, the slice selection policyfunction 114 may provide a network address of the selected network slice104 to the slice selector 110 in order to identify the selected networkslice 104. For example, the slice selection policy function 114 mayprovide the network IP (Internet Protocol) address of the gateway 112 ofthe selected network slice 104.

The slice selector 110 may communicate with the slice selection policyfunction 114 using a logical interface that is similar to the LTEDiameter Gx interface, or using any other logical interface protocol.

FIG. 2 illustrates an example method 200 that may be performed in orderto implement network slice selection in a system such as describedabove, in response to receiving a network attach request 202 such as aninitial attach request originating from the UE 102. Actions on the leftof FIG. 2 are performed by the mobility management component 108.Actions on the right of FIG. 2 are performed by network slice selector110. Although the method 200 will be described with reference to thecomponents of FIG. 1, the method 200 may also be performed in systemshaving different configurations.

An action 204 comprises receiving the network attach request 202. Theattach request 202 may be provided in accordance with LTE or 5G standardprotocols, and may indicate the IMEI (International Mobile EquipmentIdentify) of the UE 102 and an IMSI (International Mobile SubscriberIdentity) of the UE 102. The attach request may also specify an APN(Access Point Name) and an MCC/MCC (Mobile Country Code/Mobile NetworkCode). It is assumed in this example that the UE 102 is subscribed forservices with the wireless telecommunication system 100, and that thesubscriber information databases 120 include a subscriber profile and/orother information corresponding to the IMEI of the UE 102.

An action 206 comprises creating and sending a create session request208 to the network slice selector 110. The create session request may beformatted and provided in accordance with LTE and/or 5G protocols,except that it is sent to the network slice selector 110 rather than toa network mobility controller such as an SGW. Among other information,the create session request 208 indicates the IMEI, IMSI, APN, andMCC/MCN provided by the attach request 202. In LTE environments, thecreate session request 208 may be sent over an S11 logical interface asdescribed above. In 5G environments, the initial create session request208 may be sent over an NG4 logical interface.

An action 210, performed by the network slice selector 110, comprisesreceiving the create session request 208.

An action 212 comprises selecting one of multiple network slices 104and/or corresponding core networks that are available in the system 100.The selection may be based at least in part on the policies 116 and atleast in part on other information obtained from various sources. Forexample, the selection may be based at least in part on the subscriberprofile associated with the UE 102, as obtained from the subscriberinformation databases 120. The subscriber profile may, for example,indicate the type of services to which the UE 102 is subscribed,including contracted QoS parameters. The selection may also be based atleast in part on which of multiple services is associated with each ofthe available network slices and the QoS parameters provided by thenetwork slices, with a goal of matching the subscribed services of theUE 102 with a network slice that will provide those services. In somecases, the selection may additionally be based on current or historicallevels of slice congestion, in order to balance loads among existingnetwork slices.

An action 214, performed by the slice selector 110, comprisesredirecting the create session request 208 to the network slice or corenetwork that has been selected in the action 212. In certainimplementations, this may comprise sending or returning a redirectresponse 216 to the mobility management component 108, where theredirect response 216 identifies the selected network slice. Forexample, the redirect response 216 may specify the network IP address ofa gateway 112 of the selected network slice. This communication can beperformed over an S11 or NG4 interface.

An action 218, performed by the mobility management component 108,comprises receiving the redirect response 216.

An action 220 comprises sending a redirected create session request 222to the network slice or core network specified by the redirect response216. For example, the create session request 208 may be resent to thenetwork IP address specified by the redirect response 216. Theredirected create session request 222 may be formatted in accordancewith LTE or 5G protocols. Further communications and actions are thenperformed by various components of the system 100 in accordance withapplicable protocols in order to process the redirected session request222 and allow the UE to connect to the selected network slice 104.

FIG. 3 illustrates a method 300 that may be performed in certainembodiments as part of the action 212 of selecting a network slice, inresponse to the slice selector 110 receiving the create session request208. Actions on the left of FIG. 3 are performed by the slice selector110. Actions on the right of FIG. 3 are performed by the slice selectionpolicy function 114 based on the policies 116.

An action 302 comprises querying the slice selection policy function 114by sending a slice control request 304, also referred to as a slicecontrol request 304, to the slice selection policy function 114. Theslice control request 304 may be communicated using a logical interfacesimilar to the Diameter Gx interface, which is used in other parts ofLTE systems, for example. In certain embodiments, the slice controlrequest 304 may specify the IMEI and IMSI associated with the requestingUE 102. In some cases, the slice control request 304 may also specifythe APN to which the initial attach request was directed. The slicecontrol request 304 may also specify the MCC/MNC associated with the UE102.

An action 306, performed by the slice selection policy function 114,comprises receiving the slice control request 304.

An action 308 comprises querying various data sources to obtaininformation relating to slice selection. For example, the action 308 maycomprise querying the subscriber information databases 120 to obtain auser profile, which might indicate the type of services expected by theUE 102 as well as QoS levels to which the UE 102 is subscribed. Theaction 308 may also comprise querying the orchestrator 118 to determinewhich network slices are available, as well as the services andcapabilities provided by those slices. The action 308 may also comprisequerying the analytics component 122 to determine current networkcongestion in the available network slices.

An action 310 comprises evaluating the information obtained in theaction 308 against the policies 116 to identify and select one of thenetwork slices 104 that meets the needs of the requesting UE 102, basedat least in part on the policies 116. For example, a network slice maybe selected that provides the type of service expected by the UE 102 aswell as the QoS expected by the UE 102. The action 310 may also takenetwork congestion into account, and may select a network slice 104 suchthat traffic and loads are distributed evenly across the network slices104 and/or the corresponding dedicated core networks. For example, incases where more than one network slice 104 meets the needs of the UE102, the network slice having the lowest load might be selected.

An action 312 comprises returning a slice control answer 314 to thenetwork slice selector 110. The slice control answer 314 specifies theselected one of the network slices 104. In various embodiments, theslice control answer 314 may specify the network IP address of a gateway112 of the selected one of the network slices 104. The slice controlanswer 314 may be communicated using a logical interface similar to theDiameter Gx interface as mentioned above.

An action 316, performed by the network slice selector 110, comprisesreceiving the slice control answer 314. In the context of FIG. 2, thereturned network IP address of the selected network slice 104 may thenbe provided to the mobility management component as part of the redirectresponse 216.

FIG. 4 illustrates further details regarding communications between thecomponents shown in FIG. 1. In FIG. 4, communicating components orentities are shown along the top, with a corresponding dashed verticalline extending downward. Communications are indicated by arrows thatextend horizontally from and to the vertical lines corresponding to theentities from that originate and receive the communications.Communications occur in order from top to bottom. An individualcommunication or set of communications is indicated by a correspondingreference numeral along the left side of the figure, horizontallyaligned with the arrow or arrows representing the communication.

Note that FIG. 4 illustrates the most relevant communications and mayomit other communications that occur in practice but are less relevantto the topics at hand. Such other communications may includecommunications that both precede and follow the illustratedcommunications, communications that occur in time between theillustrated communications, and communications that occur betweencomponents or entities that are not specifically shown.

At 402, the UE 102 sends an initial attach request, which is received bythe mobility management component 108. The initial attach request mayinclude one or more of the IMEI of the UE 102, the IMSI of thesubscriber associated with the UE 102, an APN, and the MCC/MNCassociated with the UE 102.

In response to receiving the initial attach request, at 404 the mobilitymanagement component 108 sends a create session request to the sliceselector 110. This communication may be performed over an S11 logicalinterface in LTE environments and over an NG4 logical interface in 5Genvironments. The create session request is formatted in accordance withLTE or 5G standards and includes one or more of the IMEI, IMSI, APN, andMCC/MNC as mentioned above.

In response to receiving the create session request, at 406 the sliceselector 110 sends a slice control request to the selection policyfunction 114. The slice control request specifies the IMEI, IMSI, APN,and MCC/MNC associated with the initial attach request.

In response to receiving the slice control request, the selection policyfunction 114 selects one of multiple available network slices, asdiscussed above with reference to the action 310 of FIG. 3. At 408, theselection policy function 114 specifies the selected network slice in aslice control answer that is sent to the slice selector 110. In certainembodiments, the slice control answer specifies the network IP addressof a component, such as a gateway component, of the selected networkslice.

At 410, the slice selector sends a create session redirect response tothe mobility management component 108, specifying the selected networkslice. For example, the create session redirect response may specify thenetwork IP address that has in turn been specified by the slice controlanswer.

At 412, the mobility management component 108 is responsive to thecreate session redirect response to send a new, redirected createsession request to the selected network slice. Specifically, a secondcreate session response is sent to the network IP address of a gateway,such as an SGW, of the selected network slice. The network IP address towhich the second create session response is sent is the IP addressreturned by the slice control answer and the create session redirectresponse.

Processing of the redirected create session request then proceeds usingconventional protocols or other protocols that may be specific toparticular implementations.

FIG. 5 is a block diagram of an illustrative computing device 500 suchas may be used to implement various components discussed above, such asthe mobility management component 108, the slice selector 110, and theselection policy function 114, as well as other components of the system100 that are not specifically shown or discussed. Generally, theelements and components of the system 100 may be implemented by anynumber of computing devices 500, with the various functional and logicalcomponents being distributed in various ways across such computingdevices.

In various embodiments, the computing device 500 may include at leastone processing unit 502 and system memory 504. Depending on the exactconfiguration and type of computing device, the system memory 504 may bevolatile (such as RAM), non-volatile (such as ROM, flash memory, etc.)or some combination of the two. The system memory 504 may include anoperating system 506, one or more program modules 508, and may includeprogram data 510.

The computing device 500 may also include additional data storagedevices (removable and/or non-removable) such as, for example, magneticdisks, optical disks, or tape. Such additional storage is illustrated inFIG. 5 by storage 512.

Non-transitory computer storage media of the computing device 500 mayinclude volatile and nonvolatile, removable and non-removable mediaimplemented in any method or technology for storage of information, suchas computer readable instructions, data structures, program modules, orother data. The system memory 504 and storage 512 are all examples ofcomputer-readable storage media. Non-transitory computer-readablestorage media includes, but is not limited to, RAM, ROM, EEPROM, flashmemory or other memory technology, CD-ROM, digital versatile disks (DVD)or other optical storage, magnetic cassettes, magnetic tape, magneticdisk storage or other magnetic storage devices, or any other mediumwhich can be used to store the desired information and which can beaccessed by computing device 500. Any such non-transitorycomputer-readable storage media may be part of the computing device 500.

In various embodiment, any or all of the system memory 504 and storage512 may store programming instructions which, when executed, implementsome or all of the function functionality described above as beingimplemented by components of the system 100.

The computing device 500 may also have input device(s) 514 such as akeyboard, a mouse, a touch-sensitive display, voice input device, etc.Output device(s) 516 such as a display, speakers, a printer, etc. mayalso be included. The computing device 500 may also containcommunication connections 518 that allow the device to communicate withother computing devices.

Although features and/or methodological acts are described above, it isto be understood that the appended claims are not necessarily limited tothose features or acts. Rather, the features and acts described aboveare disclosed as example forms of implementing the claims.

What is claimed is:
 1. A wireless telecommunication system comprising: anetwork slice selector configured to send a slice request to a sliceselection policy function in response to receiving a first createsession request; a slice selection policy function configured to: selecta first network slice of multiple network slices of the wirelesstelecommunication system based at least in part on one or more policiesin response to receiving the slice request; specify the first networkslice to the network slice selector; and redirect the first createsession request to the network slice.
 2. The wireless telecommunicationsystem of 1, wherein the slice selection policy function specifies thefirst network slice by specifying a network address of a gateway of thefirst network slice.
 3. The wireless telecommunication system of 1,further comprising: a management component that receives network attachrequests from wireless communication devices, the management componentbeing configured to send a first create session request to the networkslice selector in response to receiving a network attach request from awireless communication device.
 4. The wireless telecommunication systemof claim 3, wherein the network slice selector redirects the firstcreate session request from the management component by sending aredirect response to the management component, the redirect responsespecifying the first network slice; and wherein the management componentis further configured to send a second create session request to thefirst network slice in response to receiving the redirect response. 5.The wireless telecommunication system of 1, wherein each of the multiplenetwork slices correspond to a respective dedicated core network of thewireless telecommunication system.
 6. The wireless telecommunicationsystem of 1, wherein the slice selection policy function selects thefirst network slice based at least in part on one or more of:information regarding services associated respectively with each of themultiple network slices; a subscriber profile for a wirelesscommunication device associated with the first create session request;or congestion of each of the multiple network slices.
 7. A methodperformed by a wireless telecommunications network having multiple corenetworks, the method comprising: receiving a network attach requestoriginating from a wireless communication device; sending a first createsession request to a network selector in response to receiving thenetwork attach request; and selecting, by the network selector, a firstcore network of the multiple core networks based at least in part on oneor more services associated with the first core network.
 8. The methodof claim 7, further comprising: sending a redirect response from thenetwork selector in response to the first create session request, theredirect response specifying the first core network.
 9. The method ofclaim 7, wherein selecting the first core network is further based atleast in part on a subscriber profile associated with the wirelesscommunication device.
 10. The method of claim 7, wherein selecting thefirst core network is further based at least in part on congestion ofthe core network.
 11. The method of claim 7, wherein selecting the firstcore network comprises: sending a selection request to a selectionpolicy function; and receiving a selection of the first core networkfrom the selection policy function; wherein the policy function selectsthe first core network based at least in part on one or more policies.12. The method of claim 11, wherein the one or more policies are basedat least in part on one or more of: one or more services associated withthe first core network; a subscriber profile associated with thewireless communication device; or the congestion of each of the multiplecore networks.
 13. The method of claim 7, wherein: sending the firstcreate session request is performed by a control plane function of a 5thgeneration (5G) communications network.
 14. A network selector of atelecommunications network, the network selector configured to: receivea first create session request from a management component of thetelecommunications network; select a first core network of multiple corenetworks associated with the wireless telecommunication system based atleast in part on one or more services associated with the first corenetwork; and redirect the first create session request to the first corenetwork.
 15. The network selector of claim 14, wherein the networkselector further selects the first network based at least in part on asubscriber profile of a user of a wireless communication deviceassociated with the first create session request.
 16. The networkselector of claim 14, wherein the network selector further selects thefirst network based at least in part on congestion of each of themultiple core networks.
 17. The network selector of claim 14, furthercomprising: a selection function to select the first network based atleast in part on one or more policies in response to receiving aselection request from the network selector, the one or more policiesbased at least in part on: the services associated with the firstnetwork; a subscriber profile for a wireless communication deviceassociated with the first create session request; or congestion of thefirst network.
 18. The network selector of claim 17, wherein the networkselector selects the first network by: sending the selection request tothe selection function; and receiving a selection of the first networkfrom the selection function.
 19. The network selector of claim 14,wherein the management component comprises a mobile management entity(MME) of a long-term evolution (LTE) communication network.
 20. Thenetwork selector of claim 14, wherein: the network selector is furtherconfigured to redirect the first create session request by sending aredirect response to the management component, the redirect responsespecifying the first network; and the management component is furtherconfigured to send a second create session request to the first networkin response to the redirect response.